<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Backend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: ZendServer.php 17672 2009-08-19 13:05:18Z yoshida@zend.co.jp $
 */


/** @see Zend_Cache_Backend_Interface */
require_once 'Zend/Cache/Backend/Interface.php';

/** @see Zend_Cache_Backend */
require_once 'Zend/Cache/Backend.php';


/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Backend
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
abstract class Zend_Cache_Backend_ZendServer extends Zend_Cache_Backend implements Zend_Cache_Backend_Interface
{
	/**
	 * Available options
	 *
	 * =====> (string) namespace :
	 * Namespace to be used for chaching operations
	 *
	 * @var array available options
	 */
	protected $_options = array(
        'namespace' => 'zendframework'
        );

        /**
         * Store data
         *
         * @param mixed  $data        Object to store
         * @param string $id          Cache id
         * @param int    $timeToLive  Time to live in seconds
         * @throws Zend_Cache_Exception
         */
        abstract protected function _store($data, $id, $timeToLive);

        /**
         * Fetch data
         *
         * @param string $id          Cache id
         * @throws Zend_Cache_Exception
         */
        abstract protected function _fetch($id);

        /**
         * Unset data
         *
         * @param string $id          Cache id
         */
        abstract protected function _unset($id);

        /**
         * Clear cache
         */
        abstract protected function _clear();

        /**
         * Test if a cache is available for the given id and (if yes) return it (false else)
         *
         * @param  string  $id                     cache id
         * @param  boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested
         * @return string cached datas (or false)
         */
        public function load($id, $doNotTestCacheValidity = false)
        {
        	$tmp = $this->_fetch($id);
        	if ($tmp !== null) {
        		return $tmp;
        	}
        	return false;
        }

        /**
         * Test if a cache is available or not (for the given id)
         *
         * @param  string $id cache id
         * @return mixed false (a cache is not available) or "last modified" timestamp (int) of the available cache record
         * @throws Zend_Cache_Exception
         */
        public function test($id)
        {
        	$tmp = $this->_fetch('internal-metadatas---' . $id);
        	if ($tmp !== false) {
        		if (!is_array($tmp) || !isset($tmp['mtime'])) {
        			Zend_Cache::throwException('Cache metadata for \'' . $id . '\' id is corrupted' );
        		}
        		return $tmp['mtime'];
        	}
        	return false;
        }

        /**
         * Compute & return the expire time
         *
         * @return int expire time (unix timestamp)
         */
        private function _expireTime($lifetime)
        {
        	if ($lifetime === null) {
        		return 9999999999;
        	}
        	return time() + $lifetime;
        }

        /**
         * Save some string datas into a cache record
         *
         * Note : $data is always "string" (serialization is done by the
         * core not by the backend)
         *
         * @param string $data datas to cache
         * @param string $id cache id
         * @param array $tags array of strings, the cache record will be tagged by each string entry
         * @param int $specificLifetime if != false, set a specific lifetime for this cache record (null => infinite lifetime)
         * @return boolean true if no problem
         */
        public function save($data, $id, $tags = array(), $specificLifetime = false)
        {
        	$lifetime = $this->getLifetime($specificLifetime);
        	$metadatas = array(
            'mtime' => time(),
            'expire' => $this->_expireTime($lifetime),
        	);

        	if (count($tags) > 0) {
        		$this->_log('Zend_Cache_Backend_ZendServer::save() : tags are unsupported by the ZendServer backends');
        	}

        	return  $this->_store($data, $id, $lifetime) &&
        	$this->_store($metadatas, 'internal-metadatas---' . $id, $lifetime);
        }

        /**
         * Remove a cache record
         *
         * @param  string $id cache id
         * @return boolean true if no problem
         */
        public function remove($id)
        {
        	$result1 = $this->_unset($id);
        	$result2 = $this->_unset('internal-metadatas---' . $id);

        	return $result1 && $result2;
        }

        /**
         * Clean some cache records
         *
         * Available modes are :
         * 'all' (default)  => remove all cache entries ($tags is not used)
         * 'old'            => unsupported
         * 'matchingTag'    => unsupported
         * 'notMatchingTag' => unsupported
         * 'matchingAnyTag' => unsupported
         *
         * @param  string $mode clean mode
         * @param  array  $tags array of tags
         * @throws Zend_Cache_Exception
         * @return boolean true if no problem
         */
        public function clean($mode = Zend_Cache::CLEANING_MODE_ALL, $tags = array())
        {
        	switch ($mode) {
        		case Zend_Cache::CLEANING_MODE_ALL:
        			$this->_clear();
        			return true;
        			break;
        		case Zend_Cache::CLEANING_MODE_OLD:
        			$this->_log("Zend_Cache_Backend_ZendServer::clean() : CLEANING_MODE_OLD is unsupported by the Zend Server backends.");
        			break;
        		case Zend_Cache::CLEANING_MODE_MATCHING_TAG:
        		case Zend_Cache::CLEANING_MODE_NOT_MATCHING_TAG:
        		case Zend_Cache::CLEANING_MODE_MATCHING_ANY_TAG:
        			$this->_clear();
        			$this->_log('Zend_Cache_Backend_ZendServer::clean() : tags are unsupported by the Zend Server backends.');
        			break;
        		default:
        			Zend_Cache::throwException('Invalid mode for clean() method');
        			break;
        	}
        }
}
